Search PubMed⌕ Search

Biomedical subjects

M W Johnson

Publications and source records attributed to M W Johnson.

At least 127 records · Page 7Linked to original sources

Effect of large oral doses of ascorbic acid on uric acid excretion by normal subjects.

The effects of large and oral doses of ascorbic acid on renal clearance and excretion of uric acid were studied in nongouty subjects because ascorbic acid has been reported to increase renal uric acid clearance. Our results indicate that 4 or 12 gm ascorbic acid taken in divided doses had no effect on serum uric acid concentration or uric acid excretion and clearance by the kidney. Reasons for these results, which differ from previous reports, are discussed. We quantitated the magnitude of the interference of ascorbic acid in the measurement of uric acid by the nonspecific methods frequently used, since falsely elevated urine uric acid could lead to misinterpretation of screening tests.

Administration, Oral↗

The effect of rapid weight loss due to jejunoileal bypass on total cholesterol and high-density lipoprotein.

Twelve patients undergoing a 10 to 4 inch end-to-side jejunoileal bypass for morbid obesity were measured pre- and postsurgically for total cholesterol and high-density lipoprotein (HDL) cholesterol levels. After a mean weight loss period of 7 months, results showed a significant decrease in total cholesterol (p less than 0.001) and in the total cholesterol: HDL cholesterol level (p less than 0.01). The change in HDL cholesterol levels was not significant (p less than 0.05). The decrease in total cholesterol accompanied by no change in HDL cholesterol indicates an increased transport of cholesterol as HDL in these patients. This results suggests that these subjects are placed at a decreased risk of coronary heart disease postsurgically.

Body Weight↗

The risks of asymptomatic hyperuricaemia and the use of uricosuric diuretics.

Introduction of new uricosuric diuretics will be accompanied by the unknown risk factors associated with the use of any new drug, as demonstrated by reports of hepatic toxicity associated with ticrynafen. In addition to unexpected reactions, there are potential risks related to induction of uricosuria, which are serious and have been reported to occur. More importantly, the risk of developing clinical gout or coronary heart disease due to mild asymptomatic hyperuricaemia appears minimal, so indications for the use of uricosuric diuretics are limited. If a uricosuric diuretic is thought necessary (and is available), it would seem prudent to measure the daily excretion rate of uric acid to identify those patients with hyperuricaemia related to overproduction of uric acid. A uricosuric diuretic should be avoided in those patients, as well as in patients with uric acid stones, and possibly in those with calcium stones. A uricosuric diuretic might be useful for patients with hypertension who also have hyperuricaemia due to a low excretion of uric acid.

Coronary Disease↗

Alcoholism, nonprescription drug and hepatotoxicity. The risk from unknown acetaminophen ingestion.

An alcoholic patient developed severe hepatitis and renal failure after ingesting the contents of a 300 ml. bottle of Nyquil for its ethanol content. This illness was presumably related to the 6 gm. of acetaminophen contained in this nonprescription preparation. Although hepatic damage with or without renal failure is usually described after a massive overdose of acetaminophen, the changes in drug metabolism induced by chronic ethanol consumption may increase the risk for acetaminophen toxicity. The large number of nonprescription acetaminophen-ethanol preparations available should be considered in evaluating an alcoholic patient seen with acute hepatic and renal dysfunction.

Acetaminophen↗

Temperature dependence of the chromatographic assay of hemoglobin A1 and application of a temperature controlled assay to clinical evaluation of diabetic control.

We investigated the temperature dependence of the cation-exchange chromatographic properties of hemoglobin A1 using the "Fast Hemoglobins Test System" obtained from Isolab, Inc., Akron, OH, U.S.A. and a temperature control chamber constructed in our laboratory. Six patient samples, two each from the "normal" range (5--8.5%, "transitional" range (8.5--12.0%) and "uncontrolled diabetic" range (12--20%) described by Isolab (as measured at 24 degrees C) were collected, hemolyzed and assayed according to product insert instructions. Each sample was assayed in triplicate in three separate runs at 20 degrees C, 22 degrees C, 24 degrees C, 26 degrees C and 28 degrees C in the temperature controlled (+/- 0.25 degrees C) chamber. Resultant mean increases in assay results of 0.8, 1.1 and 1.6% hemoglobin A1 per 2 degrees C increase in temperature for the three ranges respectively, indicate that the temperature dependence of the microcolumn assay for hemoglobin A1 is at least partially a function of the relative percentage of glycosylated hemoglobin in the sample. By controlling assay temperature we have reduced interassay variation throughout all concentration ranges by more than one-half to less than 5%. We applied this temperature controlled assay to measurement of hemoglobin A1 levels in 33 non-diabetic subjects and to the screening of hemoglobin A1 levels in 77 diabetic patients regularly attending the diabetic-endocrine outpatient clinic of this hospital. No non-diabetic subject had a HbA1 level above 8.5% and of the diabetic patients, 26% fell within the "normal" range, 43% within the "transitional" range and 31% within the "uncontrolled diabetic" range.

Adolescent↗

Outbreak of meningococcal disease in a family.

An outbreak of three cases of meningococcal disease occurring in a family of 14 is presented. Three of the children, between the ages of 10 months to 10 years, were hospitalized. Two of them showed positive signs of meningitis, and one had evidence of bacteremia. Neisseria meningitidis was isolated from a blood sample of one patient and a CSF sample of another. The organism was also recovered from the nasopharyngeal secretion of four other adult members of the family. All three hospitalized children were treated with parenteral penicillin and responded well to therapy. The rest of the family was treated with oral rifampin, and subsequent cultures of the nasopharynx were negative.

Carrier State↗

Treatment of tuberculosis during pregnancy.

The pregnant woman with tuberculosis who requires treatment presents a therapeutic dilemma; therefore, we reviewed all available literature on pregnant women treated with isoniazid (INH), ethambutol (EMB), rifampin (RMP), or streptomycin (SM) and report here on the relative safety of these drugs and whether the risk of teratogenesis justifies abortion on medical grounds. Other than the ototoxicity of SM, none of these drugs in normal dosages are proved teratogens to human fetuses. We recommend the use of INH in combination with EMB for a pregnant woman with tuberculosis, if the disease is not extensive. If a third drug is warranted, then RMP could be added. Because of its ototoxicity, SM should not be used, unless RMP is contraindicated or proves unsatisfactory. Routine therapeutic abortion is not medically indicated for a pregnant woman who is taking first-line antituberculosis drugs.

Abnormalities, Drug-Induced↗